The present invention relates to a device for three-dimensional examination of an object.
A device in the form of a confocal scanning microscope is described in a publication by D. K. Hamilton, et al. (Appl. Phys. B 27, 211 (1982)). Scanning microscopes with confocal beam paths, in which a so-called point light source is imaged on a plane of the object and this plane of the object is imaged on a so-called spot receiver or hole diaphragm behind which a receiver is located, have the property of being very height-selective, in other words of optically separating planes that are only a short distance apart. In the above publication, this property is used to record a surface profile of a semiconductor component. For this purpose, for each x-y position of the light spot, the object is moved in the z direction (direction of the optical axis) and the intensity curve is measured. Since the latter has a pronounced maximum when the image of the light spot is located precisely on the surface, the height of the surface in the z direction can be determined for every point in the x-y plane and the entire surface profile of the object can be recorded sequentially in this manner as a function of time.
One disadvantage of this known device is that the recording of a surface profile requires a relatively long time since only one individual object point is scanned at each point in time.
Moreover, a confocal microscope is known from U.S. Pat. No. 4,407,008 in which a one- or two-dimensional luminous diode array is imaged in the object plane. The light scattered or reflected at the object surface is then imaged on a one-dimensional or two-dimensional detector diode array. This microscope permits scanning an object without deflecting the light beam mechanically or moving the object, but here again only a single small area of the object is illuminated at each point in time so that once again a relatively long time is required to record a surface profile.